Oil feeding apparatus for reciprocating compressor

ABSTRACT

An oil feeding apparatus for a reciprocating compressor comprises: a frame unit; an oil cylinder positioned at a lower portion of the frame unit and vibrating together with the frame unit; an oil flow passage formed in the frame unit to be communicated with the oil cylinder; an oil valve placed at the frame unit, for opening/closing the oil flow passage; an oil piston movably-inserted in the oil cylinder; and springs for elastically supporting the oil piston, wherein the frame unit and the oil cylinder are integrally formed with each other. According to this, components therefor can be simplified, a distortion of the components during an assembling process can be prevented, and an oil leakage and an oil contamination can be also effectively prevented.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a reciprocating compressor, and particularly, to an oil feeding apparatus for a reciprocating compressor capable of simplifying the number of components for feeding oil to a compressing portion where gas is compressed and of preventing distortion of components during assembling process.

2. Description of the Conventional Art

In general, a reciprocating compressor is a device for sucking and compressing a refrigerant gas by a linear reciprocation of a piston in a cylinder. The reciprocating compressor may be divided into two different methods according to its driving mechanism. Namely, in one method, a rotational motion of a motor is transformed to a linear reciprocation to be then transferred to the piston, while, in the other method, a linear reciprocation of a motor is directly transferred to the piston.

FIG. 1 shows an example of a reciprocating compressor in which the linear reciprocation is directly transferred to the piston. As shown in FIG. 1, the reciprocating compressor includes: a casing 100 having a certain inner space and filled with a certain amount of oil at a bottom surface thereof; a frame unit installed at the casing 100 to be elastically supported; a driving motor 200 fixed to the frame unit, for generating a linear reciprocating driving force; a compression unit 300 for receiving the linear reciprocating driving force of the driving motor 200 to suck and compress a gas; a resonant spring unit 400 for elastically supporting in a moving direction components linearly reciprocating among components of the driving motor 200 and the compression unit 300 to induce a resonant motion; and an oil feeding unit 500 mounted on the frame unit.

The frame unit includes: a front frame 610 to which the compression unit 300 is fixedly-coupled and a part of the driving motor 200 is supported; a middle frame 620 positioned having a certain interval from the front frame 610, for fixing the driving motor 200 together with the front frame 610; and a rear frame 630 for supporting the resonant spring unit 400 together with the middle frame 620.

The driving motor 200 is comprised of: an outer stator 210 coupled between the front frame 610 and the middle frame 620; an inner stator 220 fixedly-coupled to the front frame 610 to form a certain interval with the outer stator 210; and a mover 230 inserted between the outer stator 210 and the inner stator 220 to be linearly reciprocated. The outer stator 210 has a winding coil 240 therein, and the mover 230 has a magnet 231 and a holder 232 for supporting the magnet 231.

The compression unit 300 includes: a cylinder 310 fixedly-coupled to the front frame 610; a piston 320 inserted in a compression space of the cylinder 310 to be linearly moved and coupled to the mover 230 of the driving motor 200; a suction valve 330 coupled to an end surface of the piston 320, for opening/closing a suction passage formed in the piston 320; a discharge cover 340 coupled to the front frame 610, for covering one side of the cylinder 310; a discharge valve 350 inserted into the discharge cover 340, for opening/closing the compression space of the cylinder 310; and a valve spring 360 for elastically supporting the discharge valve 350 positioned in the discharge cover 350.

The resonant spring unit 400 includes: a spring plate 410 coupled to a connection portion between the mover 230 and the piston 320; and resonant springs 420 respectively positioned at both sides of the spring plate 410.

An unexplained reference numeral 110 indicates a suction pipe, and 120 indicates a discharge pipe.

An operation the aforementioned reciprocating compressor will now be described.

First of all, once power is applied to the driving motor 200, a flux is formed at the outer stator 210 and the inner stator 220 by current flowing on the winding coil 240 of the driving motor 200. Depending on an interaction between the flux and another flux formed by the magnet 231 of the mover 230, the mover 230 is linearly reciprocated. According to the linear reciprocation of the mover 320, the piston 320 connected to the mover 320 is linearly reciprocated in the cylinder 310.

By a pressure difference of the compression space of the cylinder 310 by the linear reciprocation of the piston 320, the suction valve 330 and the discharge valve 350 open/close the gas flow passage, and then suck the gas in the cylinder 310, compress and discharge the gas. According to the repetition of those processes, the gas is continually compressed.

During sucking, compressing and discharging the gas in the compression unit 300, a vibration is generated, which is then transferred to the frame unit to thereby vibrate the frame unit. According to the vibration of the frame unit, the oil feeding unit 50 is also vibrated so as to pump the oil filled in the bottom surface of the casing 100. Then, the oil is fed to components in which a relative motion is generated, among components of the compression unit 300.

On the other hand, it will now be explained of the oil feeding unit 500 coupled to the frame unit, for pumping the oil filled in the bottom surface of the casing 100 in detail.

The oil feeding unit 500, as can be seen from FIG. 2, is comprised of: an oil pumping part mounted on a lower portion of the frame unit, for pumping oil with vibrating together with the frame unit; and an oil flow passage part for guiding the pumped oil to the compression unit 300.

The oil pumping part includes: an oil cylinder 510 pressed in the lower portion of the front frame 610 and coupled thereto; an oil piston 520 slidingly inserted in the oil cylinder 510, for pumping the oil; springs 530 positioned at each side of the oil piston 520, for elastically supporting the oil piston 520; and an oil valve 540 positioned at a front surface of the front frame 610, for opening/closing between the oil cylinder 510 and the oil flow passage part.

The oil flow passage part includes: a first oil groove 611 formed in a certain shape at a front surface of the front frame 610; and an oil cover 550 having a second oil groove 551 of a certain shape therein, and coupled to the front frame 610 to form the oil flow passage with the first oil groove 611 of the front frame 610.

The oil valve 540 is positioned between the front frame 610 and the oil cover 550, and is supported by a valve seat 560 placed between the front frame 610 and the oil cover 550.

The oil cylinder 510 is formed in a pipe shape having a certain length. A ring-shaped coupling groove 612 having a certain outside diameter and depth is formed at one side of the front frame 610. A through hole 613 connected to the first oil groove 611 is formed at an inner surface of the ring-shaped coupling groove 612. The oil cylinder 510 is coupled to the front frame 610 by being pressed in the ring-shaped coupling groove 612 of the front frame 610.

An oil suction pipe 570 is coupled to the front frame 610 to be positioned at a side portion of the oil cylinder 510. The oil suction pipe 570 is formed in a curved shape having a certain length. Also, the oil suction pipe 570 is coupled to the front frame 610 to be communicated with the first oil groove 611 of the front frame and the curved part thereof is positioned in the oil filled in the bottom surface of the casing 100.

An unexplained reference numeral 580 indicates an oil cylinder cover.

As stated above, when the oil feeding unit is vibrated together with the frame unit, the oil piston 520 is relatively moved in the oil cylinder 510. Then, the oil filled in the bottom surface of the casing 100 is pumped through the oil suction pipe 570 by a pressure difference generated in the oil cylinder 510 according to the relative motion of the oil piston 520 in the oil cylinder 510. The oil pumped through the oil suction pipe 570 is fed to the compression unit 300 through the oil flow passage part. The oil fed to the compression unit 300 is then recovered in the bottom surface of the casing 100 via the inside of the compression unit 300.

However, in the oil feeding unit of the reciprocating compressor, as shown in FIG. 3, the front frame 610 and the oil cylinder 510 are manufactured with respectively different components and then coupled to each other. As a result, because processes for manufacturing the components become complicated and processing therefor becomes precise, the manufacturing costs for the components are increased. Also, the number of components are relatively increased to thereby increase the number of assembling processes, which causes an assembling productivity to be degraded. If procedures for the processing and assembling are not completed precisely, the oil may not be pumped well and thus it may cause a lack of oil of the compression unit 300.

Furthermore, the oil cylinder 510 is pressed in by such a press to be coupled to the ring-shaped coupling groove 612 of the front frame, which causes a distortion or breakage of the thin oil cylinder 510 during the assembling process and an oil contamination due to fine debris generated by abrasion of the oil cylinder 510.

SUMMARY OF THE INVENTION

Therefore, an object of the present invention is to provide an oil feeding apparatus for a reciprocatirig compressor capable of simplifying the number of components for feeding oil to a compressing portion where gas is compressed and of preventing distortion of components during assembling therefor.

Another object of the present invention is to provide an oil feeding apparatus for a reciprocating compressor capable of preventing an oil contamination as well as an oil leakage.

To achieve these and other advantages and in accordance with the purpose of the present invention, as embodied and broadly described herein, there is provided an oil feeding apparatus for a reciprocating compressor, comprising: a frame unit having thereon a compression unit for receiving a linear reciprocating driving force of a driving motor to compress a gas, and positioned in a casing filled with oil at a bottom surface thereof to be elastically supported; an oil cylinder positioned at a lower portion of the frame unit and vibrating together with the frame unit; an oil flow passage formed at the frame unit to be communicated with the oil cylinder; an oil valve placed at the frame unit, for opening/closing the oil flow passage; an oil piston movably-inserted in the oil cylinder; and a spring for elastically supporting the oil piston, wherein the frame unit and the oil cylinder are integrally formed with each other.

Another embodiment of the present invention, there is provided an oil feeding apparatus for a reciprocating compressor comprising: a frame having a frame main body mounted with a driving motor for generating a linear reciprocating driving force and a compression unit for compressing gas by receiving the driving force of the driving motor, and an oil cylinder which is extendedly-protruded from a lower surface of the frame main body to have certain inside diameter and length; an oil piston movably-inserted in the oil cylinder of the frame; and springs for elastically supporting the oil piston.

The foregoing and other objects, features, aspects and advantages of the present invention will become more apparent from the following detailed description of the present invention when taken in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the principles of the invention.

In the drawings:

FIG. 1 is a sectional view showing a typical reciprocating compressor;

FIG. 2 is a sectional view showing an oil feeding apparatus for a conventional reciprocating compressor;

FIG. 3 is a perspective view showing an oil feeding apparatus for the conventional reciprocating compressor;

FIG. 4 is a sectional view showing a reciprocating compressor having an oil feeding apparatus in accordance with an embodiment of the present invention;

FIG. 5 is a sectional view showing an oil feeding apparatus for a reciprocating compressor according to the present invention; and

FIG. 6 is a perspective view showing the oil feeding apparatus for the reciprocating compressor according to the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Reference will now be made in detail to the preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings.

Hereinafter, it will be described in detail about an oil feeding apparatus for a reciprocating compressor in accordance with embodiments of the present invention with reference to the accompanying drawings.

FIG. 4 is a sectional view showing a reciprocating compressor having an oil feeding apparatus in accordance with an embodiment of the present invention, and FIG. 5 is a sectional view showing the oil feeding apparatus for the reciprocating compressor according to the present invention. The same portions to the conventional art have the same reference numerals.

As shown in FIGS. 4 and 5, the reciprocating compressor includes: a casing 100 having a certain inner space and filled with a certain amount of oil at a bottom surface thereof; a frame unit installed in the casing to be elastically supported; a driving motor 200 fixed to the frame unit, for generating a linear reciprocating driving force; a compression unit 300 for receiving the linear reciprocating driving force of the driving motor and then sucking and compressing a gas; and a resonant spring unit 400 for elastically supporting in a moving direction components linearly reciprocating, among components of the driving motor 200 and the compression unit 300 thereby to induce a resonant motion. This construction is similar to the aforementioned one, of which detailed explanation will be then omitted.

The frame unit has an oil feeding apparatus therein.

The frame unit includes: a front frame 640 fixedly-coupled to the compression unit 300 and to which a part of the driving motor 200 is supported; a middle frame 620 positioned having a certain interval from the front frame 640, for fixing the driving motor 200 together with the front frame 640; and a rear frame 630 for supporting the resonant spring unit 400 together with the middle frame 620.

The oil feeding apparatus includes: an oil cylinder placed at a lower portion of the front frame 640 and vibrating together with the frame unit; an oil flow passage formed at the frame unit to be communicated with the oil cylinder 641; an oil valve 540 placed at the frame unit, for opening/closing the oil flow passage; an oil piston 520 movably-inserted in the oil cylinder 641; springs 530 for elastically supporting the oil piston 520; and an oil suction pipe 645 placed at a lower portion of the front frame 640 to be communicated with the oil flow passage.

The oil cylinder 641 is integrally formed with the front frame 640 and formed in a pipe shape having certain inside diameter and length. The front frame 640 and the oil cylinder 641 are formed of the same material.

FIG. 6 shows a structure of the front frame 640. The front frame 640, as shown in FIG. 6, is comprised of: a frame main body 642 on which the driving motor 200 and the compression unit 300 are mounted; and the oil cylinder 641 formed to be extendedly-protruded from a lower surface of the frame main body 642 to have certain inside diameter and length.

The oil piston 520 is movably-inserted in the oil cylinder 641 of the frame, and the spring 530 for supporting both sides of the oil piston 520 is inserted in the oil cylinder 641.

A first oil groove 643 is formed in a certain shape at a front surface of the front frame 640 and a through hole 644 is formed to communicate the first oil groove 643 and the oil cylinder 641. An oil cover 550 having a second oil groove 551 therein of a certain shape is coupled to the front frame 640 to cover the first oil groove 643. The first oil groove 643, the second oil groove 551 and the through hole 644 form the oil flow passage.

The oil valve 540 is positioned between the front frame 640 and the oil cover 550, and is supported by a valve seat 560 placed between the front frame 640 and the oil cover 550.

The oil suction pipe 645 is formed in a curved shape. One side thereof is under the oil filled in a bottom surface of the casing 100. Preferably, the oil suction pipe 645 is integrally formed with the front frame 640.

Hereinafter, an operation effect of the oil feeding apparatus for the reciprocating compressor according to the present invention will be explained as follows.

First, the reciprocating compressor having the oil feeding apparatus according to the present invention is operated as aforementioned.

Furthermore, the oil feeding apparatus is operated as below. First, vibration in a horizontal direction is generated in the frame unit by an operation of the compression unit 300 and the driving motor 200 coupled to the frame unit. The oil piston 520 is relatively moved in the oil cylinder 641 by the vibration of the frame unit. Then, the oil filled in the bottom surface of the casing 100 is pumped through the oil suction pipe 645 by a pressure difference generated in the oil cylinder 641 according to the relative movement of the oil piston 520 in the oil cylinder 641.

The oil pumped through the oil suction pipe 645 is fed to the compression unit 300 through the oil flow passage. The oil fed to the compression unit 300 is then recovered to the bottom surface of the casing 100 through the inside of the compression unit 300.

Since the front frame 640 and the oil cylinder 641 are integrally formed in the oil feeding apparatus, the front frame 640 and the oil cylinder 641 may be manufactured by a casting.

Since the front frame 640 and the oil cylinder 641 are formed in the oil feeding apparatus according to the present invention, there is required for only one component to form the front frame 640 and the oil cylinder 641, thereby relatively simplifying a configuration of the oil feeding apparatus.

Moreover, since the front frame 640 and the oil cylinder 641 are integrally formed, there is no need to manufacture each front frame 640 and the oil cylinder 641 separately, thereby decreasing assembling processes as well as allowing easy manufacturing and processing.

Furthermore, in case of manufacturing a separate oil cylinder 641 and then assembling it into the front frame 640, the thin oil cylinder 641 may be distorted or damaged, which may cause the relative movement of the oil piston 520 not to be well achieved. However, in the present invention, because the front frame 640 and the oil cylinder 641 are integrally formed, a mis-operation of the oil piston due to a distortion of the oil cylinder 641 can be prevented thereby to feed oil smoothly.

Also, in case of manufacturing a separate oil cylinder 510 and then assembling it into the front frame 610 as the conventional art, an impurity may be generated between the oil cylinder 510 and the front frame 610 so as to contaminate the oil. However, in the present invention, since the front frame 640 and the oil cylinder 641 are integrally formed, the oil can be protected from being contaminated and prevented from being leaked out due to errors that may be occurred during manufacturing or assembling, which results in prevention of a lack of oil.

As stated so far, in the oil feeding apparatus for the reciprocating compressor in accordance with the present invention, since the number of components as well as the number of assembling processes are reduced, it is advantageous to increase assembling productivity. Also, it is effective to reduce manufacturing costs owing to a simplification of processing and manufacturing.

Furthermore, the oil can be easily fed by preventing the oil leakage and reliability of the compressor can be improved by preventing the oil contamination.

As the present invention may be embodied in several forms without departing from the spirit or essential characteristics thereof, it should also be understood that the above-described embodiments are not limited by any of the details of the foregoing description, unless otherwise specified, but rather should be construed broadly within its spirit and scope as defined in the appended claims, and therefore all changes and modifications that fall within the metes and bounds of the claims, or equivalence of such metes and bounds are therefore intended to be embraced by the appended claims. 

1. An oil feeding apparatus for a reciprocating compressor comprising: a frame unit mounted with a compression unit for compressing gas by receiving a reciprocating driving force of a driving motor and positioned to be elastically supported in a casing filled with oil at a bottom surface thereof; an oil cylinder positioned at a lower portion of the frame unit and vibrating together with the frame unit; an oil flow passage formed at the frame unit to be communicated with the oil cylinder; an oil valve placed at the frame unit, for opening/closing the oil flow passage; an oil piston movably-inserted in the oil cylinder; and springs for elastically supporting the oil piston, wherein the frame unit and the oil cylinder are integrally formed with each other.
 2. The apparatus of claim 1, wherein the frame unit and the oil cylinder are formed of the same material.
 3. The apparatus of claim 1, wherein the oil cylinder is formed in a pipe shape having certain inside diameter and length.
 4. The apparatus of claim 1, wherein an oil suction pipe is installed at a lower surface part of the frame unit.
 5. The apparatus of claim 4, wherein the oil suction pipe and the frame unit are integrally formed with each other.
 6. An oil feeding apparatus for a reciprocating compressor comprising: a frame having a frame main body mounted with a driving motor for generating a linear reciprocating driving force and a compression unit for compressing gas by receiving the driving force of the driving motor, and an oil cylinder which is extendedly-protruded from the frame main body to have certain inside diameter and length; an oil piston movably-inserted in the oil cylinder of the frame; and springs for elastically supporting the oil piston. 